The 22-year-old only joined the Billy Goats from Senshu-University during the most recent winter break, but with the Carneval city side pushing for promotion, he soon established himself as a first-team regular under head coach Peter Stöger.
"Abundance of potential"
"From the very first day I felt right at home in Köln, not just within the club, but within the team and the city as well," said Nagasawa, who made ten appearances for Köln during the second half of the season and provided one assist as they booked their place in the Bundesliga next season. "I believe that I have ideal surroundings and the best chance of developing myself further with FC and I'm delighted that the coaching staff and those in charge of the club have faith in me. I want to take on this Bundesliga challenge with 1. FC Köln and will do my best to be an ambassador for the club and the city of Köln in Japan."
Jörg Jakobs, team and youth coordinator at Köln had this to say of the youngster: "Kazuki has adapted to German football much faster than expected. He has been completely integrated into the team and made great strides during the second half of the season. We believe that he has an abundance of potential and are really pleased that together we can continue helping him evolve as a footballer."